Esther 7:10 And the king said, “Hang him on that.” So they hanged Haman on the gallows that he had prepared for Mordecai. Then the wrath of the king abated.
Opposed to taking time to think of a punishment, the king simply commanded the eunuchs to hang Haman on the gallows he had made just the day prior (5:14). Thus, Haman had paid out of his own pocket to have a torture device erected upon which he himself would be publicly executed the very next day. Then, after Haman was gone for good, the king’s anger subsided.